In mobile devices such as cellular phones that are equipped with the communication function, it has become common to have a function for retrieving a variety of information stored in a server via the WWW and a function for presenting the retrieved information to the user. Regarding retrieval of information, a technique has become popular in which the search scope is limited by the keywords obtained during the dialogue processing performed between a device and the user, so that it becomes possible to retrieve the information desired by the user in an efficient manner.
Since the user uses a mobile device while carrying it along, various conditions can be envisioned in which the mobile device is used. In the case of performing dialogue processing between a mobile device and the user, it is desirable that the details of dialogue processing are optimized according to the diverse usage conditions of the mobile device. For example, depending on various usage conditions such as what is the means of transfer for the user (car, train, walking, etc.), whether or not the device is held by the user, or whether or not the device is held near the face of the user; the most suitable dialogue processing changes.
Techniques disclosed in Japanese Patent Application Laid-open No. 2006-292596 and Japanese Patent Application Laid-open No. 2004-302734 are known for the purpose of detecting the usage condition of a device and accordingly changing the operation details. In Japanese Patent Application Laid-open No. 2006-292596 is disclosed a technique for a mobile device equipped with the GPS function. According to the technique, the means of transfer for the user is detected by processing GPS signals, and the details of the services that are provided are modified depending on the means of transfer for the user. In Japanese Patent Application Laid-open No. 2004-302734 is disclosed a technique for reading the contact Pattern of the user with respect to a device, and for selecting and executing an application program corresponding to that contact pattern.
However, in the techniques disclosed in Japanese Patent Application Laid-open No. 2006-292596 and Japanese Patent Application Laid-open No. 2004-302734, the usage conditions of a device used by a user are not evaluated in a comprehensive manner. Hence, while performing the dialogue processing with the user, the details of the dialogue processing cannot be optimized according to the usage condition of the device.